Toggle press

ABSTRACT

A programmable press is provided comprising a frame including a base, a toggle linkage mounted in the frame, a first reciprocal ram connected to the first toggle link, a second reciprocal ram connected to a second toggle link, a first thrust absorbing member, and a second thrust absorbing member for engagement between the second reciprocal ram and the first thrust absorbing member. The toggle linkage is urged away from the base, and when the toggle linkage is extended, the second ram is driven against the second thrust absorbing member, and the first ram idles a distance above the base. When the second thrust member is engaged between the first thrust absorbing member and the second ram, extension of the toggle linkage reciprocates the first ram to engage a workpiece positioned on the base.

United States Patent 1 1 1111 3,919,876

Bakermans [45] Nov. 18, 1975 1 TOGGLE PRESS 3,661,008 5/1972 Richardson72/451 [75] Inventor: Fransiscus Cornelius Bakermans, 3,795,168 3/1974Spachner 74/38 Shiremanstown, Pa.

[73] Assignee: E. I. Du Pont de Nemours & C0.,

Wilmington, Del.

[22] Filed: Nov. 11, 1974 [21] Appl. No.: 522,882

[52] US. Cl. 72/451; 72/431; 74/38; 83/630; 100/282 [51] Int. Cl. B21J9/18 [58] Field of Search 72/451, 431, 441; 100/281, 100/282; 74/38, 40;83/630 [56] References Cited UNITED STATES PATENTS 2,339,456 l/l944Budlong 83/630 2,412,924 12/1946 Stover 1 100/281 2,551,825 5/1951 Cook1 1 74/40 2,718,018 9/1955 Hildmann 100/282 2,851,888 9/1958 Scholin74/38 2,986,947 6/1961 Slettengren 74/38 3,174,347 3/1965 Hecht 74/383,270,665 9/1966 Shiokawa 100/282 Primary Examiner-C. W. LanhamAssistant Examiner-Gene P. Crosby ABSTRACT A programmable press isprovided comprising a frame including a base, a toggle linkage mountedin the frame, a first reciprocal ram connected to the first toggle link,a second reciprocal ram connected to a second toggle link, a firstthrust absorbing member, and a second thrust absorbing member forengagement between the second reciprocal ram and the first thrustabsorbing member. The toggle linkage is urged away from the base, andwhen the toggle linkage is extended, the second ram is driven againstthe second thrust absorbing member, and the first ram idles a distanceabove the base. When the second thrust member is engaged between thefirst thrust absorbing 10 Claims, 4 Drawing Figures US. Patent Nov.18,1975 Sheet10f3 3,919,876

US. Patent Nov. 18, 1975 Sheet 3 of3 3,919,876

TOGGLE PRESS BACKGROUND OF THE INVENTION 1. Field of the Invention Thisinvention relates to toggle-driven presses, and particularly relates toa press in which a tool-carrying ram is reciprocated and engaged with atooling station to perform a work function on one or more workpiecespositioned at the tooling station.

2. Description of the Prior Art Toggle-driven presses including a ramconnected to a free end of one toggle link are described in U.S. Pat.No. 2,986,947, and U.S. Pat. No. 3,174,347, U.S. Pat. No. 3,270,665 andU.S. Pat. No. 3,795,168. The above-mentioned patents describetoggle-driven presses including a toggle link adjustably connected to aframe for controlling the stroke or force of the ram. A punch pressincluding a toggle-linkage actuatable by a pair of horizontal armsconnected at one end to one of the toggle links is described in U.S.Pat. No. 2,851,888. Each arm has a slot engaging the pin of the crankand is free to idle until a trigger operated lever system is manuallyoperated to move a latch member into engagement with the horizontal armsand actuate the toggle links. Another toggle press including a first andsecond linkage of opposed angularity is described in U.S. Pat. No.3,661,008. The second toggle linkage is connected to a stationary pointand is shorter than the other link of the second toggle linkage so thatthe press slide spends a greater part of its operating cycle near thetop of its stroke removed from the thrust member, than it does near thebottom of the stroke close to the thrust member. This provides for afeed mechanism to operate over a longer interval during each cycle ofthe press.

The press of the present invention, in addition to providing increasedtime and clearance for performing feed and other functions at thetooling station under a reciprocal ram, provides for programming theengagement of tooling mounted on the ram at the tooling station at aselected interval during a machine cycle.

SUMMARY OF THE INVENTION According to the present invention, a press isprovided comprising,

a frame including a base for receiving a workpiece,

a toggle linkage operably mounted in the frame,

a first ram connected to a first link of the toggle linkage forreciprocally engaging a workpiece positioned on the base,

first thrust absorbing means fixedly mounted to the frame away from thebase,

a second ram connected to a second link of the toggle linkage forreciprocally engaging the first thrust absorbing means,

means for urging the toggle linkage away from the base so that extensionof the toggle linkage reciprocally engages the second ram with the firstthrust absorbing means while the first ram idles a spaced distance abovethe base, and,

second thrust absorbing means for engaging between the second ram andthe first thrust absorbing means, the second thrust absorbing meanshaving a thickness substantially equal to the spaced distance betweenthe first ram and said base, so that engagement of the second thrustabsorbing member between the second thrust absorbing member and thesecond ram causes the first ram to reciprocally engage the workpiecepositioned on the base when the toggle linkage is extended. First andsecond drive means are provided for, respectively, extending the togglelinkage and for engaging the second thrust absorbing means, and thirddrive means is provided connected to the first and second drive meansfor controlling the extension of the toggle linkage and the engagementof the second thrust absorbing means; so that the first ram isreciprocated to engage the workpiece at a selected interval ofa cycle ofthe third drive means Preferably, the second thrust absorbing means is amember rotated parallel to the base through the second drive means. Aspring mounted dog is provided for engaging the second thrust absorbingmember between the second ram and the first thrust absorbing means. Thesecond thrust absorbing means is spring loaded to the second drive meansto permit lost motion of the thrust absorbing member and continuousrotation of the drive means, when the second thrust member is engagedbetween the second ram and the first thrust absorbing means. A releasecam is mounted on the second drive means to disengage the dog andrelease the second thrust member from between the second ram and thefirst thrust absorbing means on completion of the press stroke of thefirst ram.

The press assembly of the present invention provides for operation athigher speeds with increased time and clearance of the reciprocal ramfor performing feed and other work functions at the tooling station,thus enabling work feed and other functions to be performed over agreater interval of the press cycle time. Additionally, the rotatablethrust member may be programmed to engage the first ram with the toolingstation during any prescribed interval over the press cycle. Thisfeature provides for driving other machine functions, e.g., workpiecefeed, in sequence with the main press drive.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagramatic view inperspective of an apparatus embodying the invention.

FIG. 2 is a partially broken-away elevation view of the apparatus ofFIG. 1.

FIG. 3 is a partially broken-away plan view of the apparatus of FIG. 1.

FIG. 4 is a partially broken-away elevation view of another apparatusembodying the invention.

DETAILED DESCRIPTION OF THE INVENTION The apparatus of the inventioncomprises a frame 10 having a base 12 with side members 14, and endmember 16. Cross members 18 and 20 and mounting plate 24 are providedbetween spaced upstanding side members 14 (one shown).

The main drive assembly 30 is mounted in frame 10. Drive assembly 30 isconnected to eccentric drive 32 which extends the press toggle drivelinkage 34. Drive assembly 30 is also connected to the thrust platedrive 36 and rotates thrust plate assembly 38 parallel to the base 12.

The drive assembly 30 includes a motor 40 mounted on base 12. Belt 41 onpulleys 43 and 45 drives main drive input shaft 42 journaled in bearings44 in side members 14. An eccentric 46 is mounted on input shaft 42. Arod 48 is connected between eccentric 46 and toggle linkage 34. Drivegear 50 on input shaft 42 drives the thrust plate drive assembly 36.

The toggle linkage 34 comprises a first toggle link 54 and a secondtoggle link 56 connected together at a knuckle 58. The knuckle 58 isconnected to the eccentric 46 through connecting rod 48. A first ram 60is pivotally connected to the free end of link 54. The first ram 60 isreciprocally disposed in guide 62 mounted on a cross member 18 betweenside members 14. A second ram 64 is pivotally connected to the free endof link 56 and with guide post 69 reciprocally disposed in guide 65mounted on a stationary vertical thrust member 66 mounted between sidemembers 14. A slot 67 is provided in one face of ram 64. A horizontalthrust member 68 is pivotally connected between the free end of link 54and pivotal mount 70 on end member 16 of frame 10. Another horizontalthrust member 72 is pivotally connected between the free end of link 56and pivotal mount 74 on end member 16 of frame 10.

The tooling station 76 is mounted on base 12 of the frame 10. Lowertooling 78 is mounted in the tooling station 76. Upper tooling 80 ismounted on the first ram 60 and is engageable with the lower tooling 78in the tooling station 76. A compression spring 82 is mounted on anothercross member between side members 14. Spring 82 biases horizontal thrustmember 72. The toggle linkage 34 is urged away from base 12, and togglelinkage 34 maintains ram 60 a spaced distance from the tooling station76 to provide clearance between the lower tooling 78 and upper tooling80. An adjustable thrust absorbing element 84 is mounted on theunderside of the cross member 20 and engages horizontal thrust member 68to limit the upward movement of the linkage 34 away from the base 12.

The thrust plate drive assembly 36 comprises thrust plate drive inputgear 90 mounted on input shaft 92 connected to right angle drive 94. Theoutput shaft of the right angle drive 94 has an output gear 98 mountedthereon. Output gear 98 drives idler gear 100 and in turn drives gear102 mounted on shaft 104. The rotatable thrust member 106 is mounted onshaft 104 for rotatable engagement between the second ram 64 and thestationary thrust member 66. A block 107 is provided on the undersidemember 106 with dog 109 for engaging slot 67 in ram 64. A compressionspring 108 is connected between the rotatable thrust member 106 and therotatable thrust member release plate 110 also mounted on shaft 104. Aguide member 112 with guide slot 114 for receiving guide pin 116 mountedon thrust member 106 is mounted on the plate 110. Rotatable thrustmember release cam 118 is mounted on plate 110. A cam surface 120 on theunderside of release cam 118 is provided for disengaging the rotatablethrust member dog 122. The dog 122 is spring mounted in block 124 andengages the rotatable thrust member when it is rotated to a positionbetween the second ram 64 and the stationary thrust member 66.Compression spring 108 permits continuous rotation of the drive shaft104 while the rotatable thrust member is engaged between ram 64 andthrust member 66 during the press stroke of ram 60. After completion ofthe press stroke, the dog is disengaged by cam surface 120 which engagescam follower 126 connected to the dog 122 and depresses the dog againstspring 128 until the rotatable thrust member is released. The dog 122 isreturned to its normal position for stopping the rotatable thrust member106 on its next revolution for engagement be tween the second ram 64 andthe stationary verticle thrust member 66.

The operation and advantages of the press assembly of the presentinvention may be readily understood with particular reference to thedrawings and the description which follows.

With the rotatable thrust member 106 rotated out of the engaged positionbetween thrust member 66 and ram 64, shaft 42 rotates the eccentric andthe toggle linkage 34 is extended. The compression spring 82 mountedbetween crossmember 20 and horizontal thrust member 72 biases the togglelinkage 34 away from the tooling station 76. The second reciprocal ram64 is driven upward a distance X and the first reciprocal ram 60 ismaintained a distance X away from the tooling station 76 by thrustelement 84 engaging horizontal thrust element 68. Assuming thereciprocal thrust member 106 is geared to rotate one revolution for onerevolution of motor 40 and eccentric 46 is geared to rotate sixrevolutions for every revolution of motor 40, the toggle linkage 34 isextended five times with the second ram being driven a distance X toengage the stationary thrust member 66. The first ram 60 is idled aspaced distance X away from the tooling station. The thrust element 84on the underside of cross member 20 and the stationary thrust member 66are spaced, respectively, a distance X from the horizontal thrust member68 and the second ram 64. This permits the first ram and the toolingmounted thereon to idle a distance X from engagement with the lowertooling 78 at the tooling station 76 during the first five extensions ofthe toggle linkage 34. On the sixth revolution of the eccentric 46, thereciprocal thrust member'l06, having a thickness X, is rotated betweenthe stationary thrust member 66 and ram 64 and engaged by the springloaded dog 122. As the eccentric is rotated through its sixthrevolution, the rotatable thrust member 106 is rotated between the firstthrust member 66 and the second ram 64. Member 106 is stopped by dog122. Extension of toggle linkage 34 causes the second ram 64 to engagemember 106 and fixes the free end of toggle link 56. The toggle linkagecauses the first ram to be moved toward the tooling station a distance Xand engage the upper tooling 80 with the lower tooling 78 at the toolingstation 76. Pin 116 on reciprocal thrust member 106 disposed in slot 114on guide member 112 and the compression spring 108 permits thecontinuous rotation of the drive 38 during the interval that thereciprocal thrust member 106 is engaged between stationary thrust member66 and the second ram 64. The cam surface 120 on thrust member releasecam 118 mounted on plate is then rotated into engagement with camfollower 126 and the dog 112 is depressed in mount 124 against spring128 until the reciprocal thrust member 106 is released when the togglelinkage 34 is retracted. Compression spring 108 advances the reciprocalthrust member 106 until guide pin 116 engages the end of slot 114 onguide member 112 in the direction of rotation of the plate 110. The ram60 is again allowed to idle during the next five revolutions of theeccentric 46 providing an ample time interval and sufficient clearancebetween the lower tooling 78 and the upper tooling 80 to provide forother work functions at the tooling station 76, e.g., the advance of theworkpiece and the feeding of another workpiece to the tooling station.

FIG. 4 illustrates a machine embodying the press of the presentinvention. The same numerals are used in this figure to identify thesame element as in the other figures.

The press of the present invention is particularly useful in conjunctionwith machine tools when a precisely controlled and timed press stroke isrequired. The timing and displacement of the press stroke ismechanically inter-related to the main drive and may be interrelated toall other machine functions by drive means off the main drive assembly.For example, it may be desirable to provide a number of machinefunctions within each revolution of the main drive motor. For example,feeding a first workpiece in a first direction to the tooling station,feeding a second workpiece in a second direction to the tooling station,feeding a third workpiece in a third direction to the tooling station,and feeding a fourth workpiece in a fourth direction to the toolingstation. Then performing a work function on the workpieces using a pressstroke and then removing the workpiece upon which the work function hasbeen performed from the tooling station. The press assembly of thepresent invention readily provides for such a sequence of workfunctions, wherein a number of work functions is performed at the workstation previous to the press function and only a single work functionis required after completion of the press stroke, or where the number ofwork functions is the same before and after the press stroke.Additionally, the press stroke can be accurately and repeatably providedat a given interval in each revolution of the main drive by selectingthe desired gear ratio and setting up the main drive to drive anyancilliary work functions in sequence with the eccentric 46 connected tothe toggle linkage 34 and the reciprocal thrust member drive 36.

While a preferred embodiment of the press assembly of the presentinvention is desribed above, it being apparent that other embodimentsand modifications will be obvious to one of ordinary skill in the art;the invention is not to be limited except by the appended claims.

What is claimed is:

l. A press comprising,

a frame including a base for receiving a workpiece,

a toggle linkage operably mounted in said frame,

a first ram connected to a first link of said toggle linkage forreciprocally engaging a workpiece positioned in said base,

first thrust absorbing means fixedly mounted on said frame away fromsaid base,

a second ram connected to a second link of said toggle linkage forreciprocally engaging said first thrust absorbing means,

second thrust absorbing means for engaging between said second ram andsaid first thrust absorbing means, said second thrust absorbing meanshaving a thickness substantially equal to the spaced distance betweensaid first ram and said base, so that engagement of said second thrustabsorbing means between said first thrust absorbing means and saidsecond ram causes said first ram to reciprocally engage the workpiecepositioned on said base when said toggle linkage is extended.

2. A press, as recited in claim 1, wherein said second thrust absorbingmeans is a member rotatable parallel to said base.

3. A press, as recited in claim 1, additionally comprisi g;

means for urging said toggle linkage away from said base so thatextension of said toggle linkage reciprocally engages said second ramwith said first thrust absorbing means while said first ram idles aspaced distance above said base.

4. A press, as recited in claim 2, additionally comprisinga spring'mounted dog mounted. on said framefor engaging said rotatable thrustmember, when said member is rotated into engagement between said firstthrust absorbing means and said second ram.

5. A press, as recited in claim 4, additionally comprising means forreleasing said dog and said rotatable thrust absorbing member fromengagement between said first thrust absorbing means and said secondram.

6. A press comprising,

a frame including a base having a tooling station mounted thereon forreceiving a workpiece,

a toggle linkage operably mounted in said frame,

a first ram connected to a first link of said toggle linkage forreciprocally engaging tooling mounted thereon with a workpiecepositioned at said tooling station,

first thrust absorbing means fixedly mounted on said frame above saidtoggle linkage,

a second ram connected to a second link of said toggle linkage forreciprocally engaging said first thrust absorbing means,

means for urging said toggle linkage away from said base so thatextension of said toggle linkage reciprocally engages said second ramwith said first thrust absorbing means while said tooling mounted onsaid first ram idles a spaced distance above said tooling station,

second thrust absorbing means for engaging between said second ram andsaid first thrust absorbing means, said second thrust absorbing meanshaving a thickness substantially equal to the spaced distance betweensaid tooling mounted in the first ram and the tooling station, so thatengagement of said second thrust absorbing means between said firstthrust absorbing means and said second ram causes said first ram toreciprocally engage the tooling mounted thereon with the workpiecepositioned at said tooling station,

first drive means mounted in said frame for extending said togglelinkage,

second drive means mounted on said frame for continuously rotating saidsecond thrust absorbing means, and

third drive means operably connected to said first and second drivemeans for controlling the extension of said toggle linkage and theengagement of said second thrust absorbing means between said firstthrust absorbing means and said second ram so that the tooling mountedon the first ram engages the workpiece at the tooling station at aselected interval of a cycle of said third drive means.

7. A press, as recited in claim 6, additionally comprising a pair ofhorizontal support members, each member pivotally connected between eachtoggle link of said toggle linkage and said frame.

8. A press, as recited in claim 7, wherein said means for urging saidtoggle linkage away from said base comprises a spring mounted on across-member mounted on said frame, said spring mounted between saidcrossmember and one of said horizontal support members.

9. A press, as recited in claim 6, wherein said second drive means is aright angle drive, said second thrust absorbing means is a memberrotatable parallel to said base, and said rotatable member is driven ata ratio of 1:1 by said third drive means.

10. A press, as recited in claim 9, wherein said first drive means is aneccentric, and said eccentric is driven at a ratio of greaterthan 1:! bysaid third drive means.

1. A press comprising, a frame including a base for receiving aworkpiece, a toggle linkage operably mounted in said frame, a first ramconnected to a first link of said toggle linkage for reciprocallyengaging a workpiece positioned in said base, first thrust absorbingmeans fixedly mounted on said frame away from said base, a second ramconnected to a second link of said toggle linkage for reciprocallyengaging said first thrust absorbing means, second thrust absorbingmeans for engaging between said second ram and said first thrustabsorbing means, said second thrust absorbing means having a thicknesssubstantially equal to the spaced distance between said first ram andsaid base, so that engagement of said second thrust absorbing meansbetween said first thrust absorbing means and said second ram causessaid first ram to reciprocally engage the workpiece positioned on saidbase when said toggle linkage is extended.
 2. A press, as recited inclaim 1, wherein said second thrust absorbing means is a memberrotatable parallel to said base.
 3. A press, as recited in claim 1,additionally comprising; means for urging said toggle linkage away fromsaid base so that extension of said toggle linkage reciprocally engagessaid second ram with said first thrust absorbing means while said firstram idles a spaced distance above said base.
 4. A press, as recited inclaim 2, additionally comprising a spring mounted dog mounted on saidframe for engaging said rotatable thrust member, when said member isrotated into engagement between said first thrust absorbing means andsaid second ram.
 5. A press, as recited in claim 4, additionallycomprising means for releasing said dog and said rotatable thrustabsorbing member from engagement between said first thrust absorbingmeans and said second ram.
 6. A press comprising, a frame including abase having a tooling station mounted thereon for receiving a workpiece,a toggle linkage operably mounted in said frame, a first ram connectedto a first link of said toggle linkage for reciprocally engaging toolingmounted thereon with a workpiece positioned at said tooling station,first thrust absorbing means fixedly mounted on said frame above saidtoggle linkage, a second ram connected to a second link of said togglelinkage for reciprocally engaging said first thrust absorbing means,means for urging said toggle linkage away from said base so thatextension of said toggle linkage reciprocally engages said second ramwith said first thrust absorbing means while said tooling mounted onsaid first ram idles a spaced distance above said tooling station,second thrust absorbing means for engaging between said second ram andsaid first thrust absorbing means, said second thrust absorbing meanshaving a thickness substantially equal to the spaced distance betweensaid tooling mounted in the first ram and the tooling station, so thatengagement of said second thrust absorbing means betwEen said firstthrust absorbing means and said second ram causes said first ram toreciprocally engage the tooling mounted thereon with the workpiecepositioned at said tooling station, first drive means mounted in saidframe for extending said toggle linkage, second drive means mounted onsaid frame for continuously rotating said second thrust absorbing means,and third drive means operably connected to said first and second drivemeans for controlling the extension of said toggle linkage and theengagement of said second thrust absorbing means between said firstthrust absorbing means and said second ram so that the tooling mountedon the first ram engages the workpiece at the tooling station at aselected interval of a cycle of said third drive means.
 7. A press, asrecited in claim 6, additionally comprising a pair of horizontal supportmembers, each member pivotally connected between each toggle link ofsaid toggle linkage and said frame.
 8. A press, as recited in claim 7,wherein said means for urging said toggle linkage away from said basecomprises a spring mounted on a cross-member mounted on said frame, saidspring mounted between said cross-member and one of said horizontalsupport members.
 9. A press, as recited in claim 6, wherein said seconddrive means is a right angle drive, said second thrust absorbing meansis a member rotatable parallel to said base, and said rotatable memberis driven at a ratio of 1:1 by said third drive means.
 10. A press, asrecited in claim 9, wherein said first drive means is an eccentric, andsaid eccentric is driven at a ratio of greater than 1:1 by said thirddrive means.